Black screen, until running xawtv

[cracklincrotch]

It's weird. I've set up zoneminder before. I've had black screens and fixed them. But the problem I'm having on this box is ZoneMinder shows a black screen until I run xawtv. Then everything works fine.

Installed ZM 1.22.3 on Slackware 10.2, running kernel 2.6.21, with two BT878 cards. I'm not getting any errors in my debug logs. In fact, it says it's capturing frames..

May 1 09:03:34 1500-768 zmc_dvideo1[2426]: INF [new2: 15000 - Capturing at 17.86 fps]
May 1 09:04:04 1500-768 zmc_dvideo3[2434]: INF [New4: 26000 - Capturing at 29.41 fps]
May 1 09:04:05 1500-768 zmc_dvideo2[2430]: INF [New: 26000 - Capturing at 29.41 fps]
May 1 09:04:06 1500-768 zmc_dvideo7[2601]: INF [New7: 20000 - Capturing at 30.30 fps]

zmfix appears to be doing its job because the /dev/v4l/video? are correct for the inputs I have monitored (being 0, 1, 2, 3, and 7)

crw-rw-rw- 1 root video 81, 0 2007-04-27 14:59 /dev/v4l/video0
crw-rw-rw- 1 root video 81, 1 2007-04-27 13:04 /dev/v4l/video1
crw-rw-rw- 1 root video 81, 2 2007-04-27 13:04 /dev/v4l/video2
crw-rw-rw- 1 root video 81, 3 2007-04-27 13:05 /dev/v4l/video3
crw-rw---- 1 root video 81, 4 2007-04-27 13:05 /dev/v4l/video4
crw-rw---- 1 root video 81, 5 2007-04-27 13:05 /dev/v4l/video5
crw-rw---- 1 root video 81, 6 2007-04-27 13:06 /dev/v4l/video6
crw-rw-rw- 1 root video 81, 7 2007-04-27 13:06 /dev/v4l/video7
crw-rw---- 1 root video 81, 8 2007-04-27 13:06 /dev/v4l/video8

Now as soon as I run "xawtv -c /dev/video?" zoneminder then switches from a black screen to what the camera sees. I have to do that again for each input. If I restart the machine, it's the same thing.

Open to ideas, criticisms, flames, etc.

[Draco]

Unfortunately you never got a reply, because I'm having the same EXACT issue.

This is on a 2.6.21.5 kernel running Ubuntu Feisty Fawn 7.04 w/ a 8pt capture card from Bluecherry (CV-SDC880)

I've spent countless hours just trying to get rid of the black screen. I had a fun time w/ the long bttv delays of detection on boot until I found the command to shorten that. (it was options i2c-algo-bit bit_test=1 that fixed it in modprobe.d/options) I've even went as far as to disable overlay support on bttv - and all that gets me are shared memory errors.

NOTE: I can SLIGHTLY see something come on the screen when the camera is plugged in! It's a tiny sliver of white-ish feed about 1px in size at the top of the picture. (and again, if I activate xawtv on that dev interface, it will display the picture just fine... until I reboot.)

Did you happen to fix this issue? I would love to know.

And if anyone else has any insight on this, I'd really really appreciate a reply to this. I'm in dire need at getting this to work.

[tgutwin]

Same issues... seems to be a kernel module issue with the latest kernel.
See Jul 8 post by tgutwin at this other thread...

http://www.zoneminder.com/forums/viewtopic.php?t=9414

Update....

Its actually a V4L 1 loading issue.
see http://www.zoneminder.com/forums/viewtopic.php?t=10108 that describes what happens if a v4l1 app grabs the device first.